(CBS/AP) Around 20 foreign women were involved in the alleged prostitution scandal that has led to investigations into potential misconduct by U.S. Secret Service agents and military personnel, a senator briefed on the probe said.
Sen. Susan Collins, R-Me., said Tuesday that 20 or 21 women were brought back to a hotel in Cartagana, Colombia in the scandal that led to the recall of 11 Secret Service agents ahead of the President Obama's arrival for a weekend summit. Collins said U.S. Marines are also alleged to have been involved.
Collins was briefed on the probe Monday night by Mark Sullivan, director of the Secret Service. She said she raised questions about whether the women involved could have posed a security threat to the president.
The 11 Secret Service members, a group including agents and uniformed officers, are alleged to have hired prostitutes at the hotel.
The White House said on Tuesday that President Obama has confidence in Sullivan and that he performed promptly in the situation, Reuters reported.
Meanwhile, Congressman Peter King, the chairman of the House Homeland Security Committee, said this is no time to oust Sullivan, based on what is known so far about the recall of 11 agents from Colombia.
The New York Republican also tells NBC's "Today" show Tuesday that Sullivan "acted immediately" and says he thinks "it's wrong to be prejudging Mark Sullivan."
But King also says, quote, "It looks like we really lucked out on this," telling NBC it appears agents compromised presidential security with the partying that occurred in Colombia before President Barack Obama arrived for his summit in Cartagena, Colombia.
King says, "You don't allow a potential enemy into your security zone."
The Secret Service personnel were placed on administrative leave and on Monday the Secret Service announced that the agency had also revoked thier security clearances. That means they cannot enter Secret Service facilities or facilities guarded by the Secret Service, said agency spokesman Brian Leary.
Though on leave, the agents and officers will continue to be paid.
A defense official told CBS News that more than 10 military personnel are also being investigated for their involvement.
The military members were staying at the same hotel, Pentagon press secretary George Little said Monday.
"We let the boss down," Army Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, told a Pentagon news conference Monday. He said he regretted that the scandal diverted attention from Mr. Obama's diplomacy at a Latin America summit.
"I can speak for myself and my fellow chiefs: We're embarrassed by what occurred in Colombia, though we're not sure exactly what it is," Dempsey added.
Appearing with Dempsey at the Pentagon, Defense Secretary Leon Panetta said U.S. troops are expected to abide by "the highest standards" of behavior whether they are at home or abroad. He noted that a military investigation is under way and promised that if wrongdoing is confirmed, "these individuals will be held accountable."
Army Col. Scott Malcom, chief spokesman for U.S. Southern Command, which organized the military team that was assigned to support the Secret Service's mission in Cartagena, declined to say how many additional service members are under investigation. He also would not say which branch of the military they were from.
"We are still putting together all the facts," Malcom said.
A defense official in Washington said at least some of those under investigation are members of the Army. The official spoke on condition of anonymity because the matter is under active investigation.
Malcom said a colonel from the Southern Command staff, whom he would not identify by name, had been sent to Cartagena to gather facts. He said at least five military members under investigation were being flown to Miami on Monday.
The U.S. Southern Command had announced on Saturday that five service members assigned to the presidential mission in Colombia had violated curfew and may have been involved in "inappropriate conduct." A Pentagon official later told CBS News that the number involved may actually be more than 10.
In a statement Saturday, Air Force Gen. Douglas Fraser, commander of Southern Command, said he was "disappointed by the entire incident" and that "this behavior is not in keeping with the professional standards expected of members of the United States military."
"I expect that investigation to be thorough, and I expect it to be rigorous," Mr. Obama said Sunday. "If it turns out that some of the allegations that have been made in the press are confirmed, then of course I'll be angry. ... We are representing the people of the United States, and when we travel to another country, I expect us to observe the highest standards."
California Rep. Darrell Issa, chairman of a House investigative panel, said he wasn't certain whether Congress would hold hearings on the alleged misconduct. But lawmakers will be looking "over the shoulder" of the Secret Service, he said, to make sure that the agency's methods for training and screening agents aren't endangering the nation's VIPs.